Add a generic function to modify the button assignments

This should support a per-player option in the future.
Rewrite the key assignment function to override default key
Set default value for custom key assign to false on first load
Move rating to a menu option. Use resources for 2.3 dialog
Remove unnecessary Ouya import from Moga (copy-paste)
Support per-player moga config, Disable pro config for now
Support per-player moga config, Cleanup the rating change
Merge pull request #134 from NoblesseOblige/master

Feature request : key mapping / Rate reicast menu